The invention relates generally to the field of medical data processing and, more specifically, to techniques for smoothing of dynamic image data sets.
Computed tomography (CT) is an imaging technology commonly used to diagnose diseases internal to the human body. To diagnose acute stroke, for example, medical staff may employ a series of distinct CT examinations, such as non-contrast CT (NCT), CT angiography (CTA), and/or CT perfusion. Generally, a CT perfusion examination may involve providing an iodine contrast in a patient's bloodstream and continuously imaging the patient, typically for around 30-60 seconds with photos captured every 1-3 seconds. A data set resulting from a CT perfusion examination has historically enabled assessment of cerebral ischemic regions. In contrast, NCT has been used to rule out cerebral hemorrhage, while CTA has been used to rule out a brain aneurysm.
Recently, new CT imaging techniques such as Volume Shuttle and Helical Shuttle have expanded the capabilities of CT perfusion. The new techniques may enable extraction of both NCT and CTA data from a single CT perfusion examination, potentially eliminating separate NCT and CTA examinations. CT perfusion examinations may provide further benefits, as dynamic (4D) review of CT perfusion data may enable visualization and assessment of the flow of contrast agent through vasculature of interest, as well as provide differentiation between arterial and venous phases.
Certain limitations to CT perfusion remain. For example, in some cases, spatial resolution and overall quality of CT perfusion data sets may be worse than static data sets, and partial-volume artifacts may be unavoidable. Moreover, the 4D visualization of dynamic CT perfusion data may suffer from temporal sampling limitations, minimization of dose causing a low signal-to-noise ratio (SNR), patient motion, registration, beam hardening, as well as other artifacts.